In a bowl, combine pretzels and sugar; mix well. Cut in butter until mixture resembles coarse crumbs. Press into a 14-inch pizza pan. Bake at 375 degrees for 8-10 minutes or until set. Cool on a wire rack; refrig-erate for 30 minutes. Meanwhile, in a bowl, combine milk, lime juice and peel. Fold in whipped topping; spread over crust. Cover and chill. Top with fresh fruit just before serving.